Speculation has mounted in recent months that the 27-year-old from Bolton will get his dream showdown against the unbeaten world light-middleweight champion in Las Vegas in May.

And speaking to Press Association Sport, Khan said: "It's the fight I've always been after and we're very close now, not too far away. Hopefully something is going to be announced within the next couple of weeks."

Khan would effectively have to step up a weight division to take on Mayweather, but can take heart from recent upsets in the sport, including Adrien Broner's defeat at to Khan's former foe Marcos Maidana at the weekend.

Khan added: "Boxing's all over the place at the moment with all the underdogs coming through to win.

"Porter was the underdog against Alexander then Broner was beaten and knocked down by Maidana. It's the time of the underdogs.

"If I get the fight against Mayweather I have no doubt I can go and take it."